You've got the lastest result from each call in the service detail. Takine any service in any status, if you click on the service name from the monitoring view you get the detail where you could find latest check results.
Service Status OK
Disk OK - / TOTAL: 19.686GB USED: 5.418GB (27%) FREE: 14.268GB (73%)
Performance Data size=21137846272B used=5817847808B;16910277017;19024061644;0;21137846272
Current Attempt 1 / 3
State Type HARD
Last Check Type Active
Last Check 2011/05/18 - 13:59:24
Next Scheduled Active Check 2011/05/18 - 14:59:24
Latency 0.86 seconds
Here the performance data is:
Performance Data size=21137846272B used=5817847808B;16910277017;19024061644;0;21137846272. It's in fact the last part returned in the check output (after the pipe).
To check how centreon handle that 'perfdata' you should Go to
administration>Options>Centstorage>Manage, Here you can see for each service/host which metrics are extracted from the performance data string.
To get these metrics on a graph check that you've got it on
Views>Graphs>Curves. You can easily create a new ones (with maybe not enought options, but for simple metrics it will be enough).